Circuit closing device



CIRCUIT CLOSING DEVICE Filed July 25, 1945 2 Sheets-$heet l //v l/ENTORA. K SCHENCK ATTORNEY April 24, 1951 A. K. SCHENCK CIRCUIT CLOSINGDEVICE 2 Sheets-Sheet 2 Filed July 25, 1945 .II. R J m H r N C H a w v wK an no A k xbbmtu .22: 35% a main ATTOR EV Patented Apr. 24, 1951UNITED STATES PATENT OFFICE.

CIRCUIT CLOSING DEVICE Alfred K. Schenck, East Orange, N. J., assignorto Bell Telephone Laboratories, Incorporated, New York, N. Y., acorporation of New York Application July 25, 1945, Serial No. 607,055

- 11 Claims. i

This invention relates in general to electromagnetic circuit-closingdevices and in particular to a modification of the relay disclosed byWalter B. Ellwood in United State Patent 2,289,830.

An object of the invention is to facilitate adjustment of the period ofclosure of a magnetically responsive switch. Another object is to secureaccurate time relation between the actuation of a magnetic switch andthe movement of a control element.

Still another object is to secure synchronism between the periodic orregular motion of a mechanical member and the operation of switchcontacts.

Another and more particular object of this invention is to provide amore efiicient means for synchronizing the operation of auxiliarycircuits with the sweep of the antenna beam in certain types of radiosystems.

In embodiments of the invention hereinafter to be described in detail apair of hermetically sealed resilient magnetic contact members areinterposed in a gap in a magnetic circuit comprising magnetic material,and control means operate to Vary the magnetic flux in the magneticcircuit and thereby to elTect operation of the contact members. Thecontrol means may take the form of a magnetic member, that is, either anelement of paramagnetic material or a permanently magnetized memberarranged to be interposed in and withdrawn from a gap in the magneticcircuit, whereby to vary the operating flux associated with themagnetomotive force that is provided by either permanent magnetizationof some part of the magnetic circuit or by an electric-current carryingcoil enclosing some part thereof. More particularly, as will appear, themagnetic control member is arranged to be rotated in or through the gapin the magnetic circuit to provide operation of the switch insynchronism with the movement of a connected rotary element. Inaccordance with an important feature variable magnetic bias is providedby a current-carrying coil whereby the time of closure and the time ofrelease of the contacts are accu rately adjustable in relation to themovement of the magnetic control element.

A particular advantage of the present inven-- tion i that it is adaptedfor use in installations which are inaccessible for ordinary adjustmentor servicing by an operator by virtue of providing a remote controlfeature. 1

Devices in accordance with the present inven-' ticn are thereforeparticularly adapted tc meet the stringent requirements of a controlsystem for auxiliary antenna operations such as disclosed in thecopending application of C. N. Nebel, Serial No. 607,054, now Patent No.2,518,561, filed ofeven date herewith. The disclosure of the said Nebelapplication is to be deemed, incorporated herein.

In accordance with one specific embodiment of the present invention. therelay comprises a soft iron core having two gaps. In one of the gaps idisposed a glass-enclosed relay having a pair of resilient magneticcontacts. A permanent magnet mechanically connected to a periodicallymoving member is adapted to move in and out of the second gapperiodically, causing the core to become magnetized periodically wherebythe magnetic contacts are actuated to open and close at regularintervals. A bias winding disposed on the soft iron core functions toindependently control the points of closure and release of the contactsin accordance with adjustments in resistance elements in a controlcircuit connectedthereto because relay operation in the control circuitis adapted to change the current in the bias winding upon closure andrelease of the resilient contacts.

In accordance with a second embodiment of the invention the relaycomprises a core having a pair of soft iron legs, one of which has anener-v gizing electrical winding thereon, and the other of whichcontains in a gap thereof a longitudinally disposed glass-enclosed relayhaving resilient magnetic contacts. The two legs are held in parallelrelation bya pair of spacers, one com-. prising magnetic material whichis disposed to complete the magnetic circuit at one end of the relay,and the other comprising non-magnetic material, and disposed near theopposite end. Adjacent the latter end rotates a disk comprising anon-magnetic material upon which i mounted a soft iron shoethereby'varying the reluctance of the magnetic circuit and causingclosure of the resilient contacts. The points of closure and release arerelated to the currents in the energizin winding at different times inthe disk rotational cycle. These currents are adjustable by an auxiliarycontrol circuit comprising a pair of variable resistances in parallel. Ain the previous embodiment, a conventional electromagnetic relay isincluded in the auxiliary control circuit which is responsive to theclosure and release of the resilient contacts to change the current inthe bias winding.

The invention will be better understood by a study of the detaileddescription hereinafter, and the drawings, which show severalembodiments of relays in accordance with the present invention and theirrelation to the auxiliary control system disclosed in the application ofC. N. Nebel cited hereinbefore.

Fig. 1 shows an embodiment of the present invention in which a relay ofthe type disclosed by Ellwood supra is positioned in one gap in a softiron yoke, while a permanent magnet attached to the antenna shaftperiodically moves in and out of a second gap;

Fig. 2A shows a control circuit such as disclosed in the copendingapplication of C. N. Nebel, which includes a magnetically actuatedcircuit breaker designed according to the present invention;

Fig. 2B shows an enlarged and detailed schematic view of the switch 60included in the system of Fig. 2A of the drawings,

Fig. 3 shows an enlarged and detailed view of the relay incorporated inFig. 2A, which comprises a soft iron shoe attached to an aluminum diskwhich rotated in and out of the field of an electromagnet toperiodically actuate an Ellwood relay.

The structure and operation of one embodiment of the invention will nowbe described with reference to Fig. 1. The relay there shown comprises ahorseshoe-shaped yoke I I formed of two symmetrical L-shaped members ofsoft-iron, wherein the outwardly-directed legs of the said members areseparated by a relatively large gap 30 and the inwardly-directed legs ofthe said members are separated by a relatively smaller gap 5. The relayI B of the type disclosed by Ellwood supra, which is positionedlengthwise in the gap 5 of the yoke II, comprises resilient contactstrips I2 and I2 comprising pure iron or other magnetizable materialwhich are hermetically sealed in the glass tube I3 encased in aprotective non-magnetic sleeve I4. The contacts I2, I 2 are so disposedthat the longitudinal dimensions thereof are substantially aligned withthe direction of flux passing through the magnetic circuit comprisingthe yoke II. The contact I2 is connected to ground 25', and the contactI2 is connected to a circuit which includes the electromagnetic relay 25and the energizing battery 21.

The permanently magnetized bar magnet I5 is attached to the antennadrive shaft I6 by means of the arm I1 which is mounted rigidly on theshaft and rotated therewith. To the permanent magnet I5, the adjustablepole-pieces I8 and I8 are attached by means of the filisterhead ironmachine screws I9 and I9.

Rotation of the permanent magnet I5 in and out of the gap 30 causes aperiodic change in the magnetic flux passing through the yoke I I,thereby causing the periodic closure of the magnetic contacts I2 and I2.The interval of closure of the contacts I2 and I2 is controlled by thecurrent in the control winding 20, which is wound about the yoke II insuch a manner as to produce the magnetic polarity indicated, that is, tooppose the induced flux produced by magnet I5.

Current is fed into the control winding 20 from the battery 2|, and isregulated by means of a control circuit which functions as follows. Whenthe relay 25 is unoperated, that is, when the contacts I2 and I2 areopen, current from the battery 2| flows through the resistance 22, thearmature 24 and its a contact, the rheostat 26, the brush 28, theresistance 23 and through the winding control 20 to ground. When therelay 25 is operated, that is, when the contacts I2 and I2 are closed,current from the battery 2I flows 4 through the resistance 22, thearmature 24 and its b contact, the rheostat 21 and its brush 23, theresistance 23 and the winding 28 to ground.

In order to adjust the exact positions of opening and closing of thecontacts I2 and I2 with respect to the position of the antenna beam, thefollowing initial adjustments are made in the control rheostats 26 and21. With the relay 25 deenergized as the magnet I5 swings into place inthe gap 30, the position of closure of the contacts I2 and I2 isadjusted by means of the brush 28 on the rheostat 26. Similarly, withthe relay 25 operated, as the rotating magnet I5 moves out of the gap 3!the opening position of the contacts I2 and I2 is adjusted by means ofthe brush 29 on the rheostat 2I. Rough adjust ments may be made bychanging the positions of the pole-pieces l8 and I8 with theirrespective screws I9 and I9, thereby slightly adjusting the clearancebetween the ends of the yoke II and the magnet I 5 as it passes throughthe air-gap 30.

Certain advantages are inherent in any relay designed according to thepresent invention which employs a permanent magnet-either a movablemember such as the rotating member I5, or a fixed permanent magnet whichmight replace the yoke II. In case of voltage failure in the controlwinding, the switch still operates, although remote control over theinterval of contact closure is lost,

It is an important feature of the invention that the circuit for thecontrol winding 29 is of such a nature that it may be located in aposition quite remote from the main relay structure. For instance, inairplane installations, the relay structure may be positioned in thewing of the plane for convenient proximity to the antenna while thecontrol rheostats 28 and 2? may be positioned on the instrument panelaccessible for adjustrnent by the operator.

An embodiment of the present invention particularly designed forairplane use is incorporated in the auxiliary antenna control circuitshown in Fig. 2A, which is disclosed in the copending application of C.N. Nebel, Serial No. 607,054. A detailed view of the relay of thepresent invention is shown in Fig. 3.

For a detailed description of the structure and operation of theauxiliary antenna control circuit shown in Fig. 2A, reference may bemade to the disclosure of the Nebel application supra, in which it willbe noted that Figs. 1A and 1B exactly correspond to Figs. 2A and 2B inthe present application.

The embodiment of the invention shown in Figs. 2A, 2B and 3 utilizes anelectromagnet having a soft iron core, the reluctance of the magneticcircuit being varied by the rotation of a disk comprising magnetic andnon-magnetic portions. The respective points of closure and release ofthe contacts of the Ellwood type contactor included in the magneticcircuit are regulated by variations in the currents in the energizingwinding.

In Figs. 2a, 2b and 3, the relay 60, which is of the type disclosed inPatent 2,289,830 to Walter B. Ellwood, July 14, 1942, comprises a pairof iron strips 62 and 62 with amalgamated tips which are hermeticallysealed in a longitudinal position in the glass envelope 63. The relay 60is fitted into the recessed ends of the zinc-plated magnetic iron poles64 and 64'. An electromagnet III, which is wound on the soft iron coreII, is held by means of the spacers "I2 and I3 in a position parallel tothe relay 60, so that the latter lies in the path of the magnetic flux.The

spacer 12 comprises zinc-plated magnetic iron, while the spacer 13comprises non-magnetic alumlnum. The zinc-plated magnetic iron legs 14and 15 protrude through the holes in the aluminum spacer 73 to enclosethe. air-gap 16.

The disk 65, which comprises an aluminum yoke 11 and soft iron shoe [8,is rigidly fixed on the antenna cam drive shaft 66 which is rotated bymeans of the antenna. motor 41 as described in the application of Nebelcited hereinbefore. When the soft iron shoe '!8 rotates into positionclosing the gap between the legs 14 and 15, the reluctance of themagnetic circuit is sufficiently reduced to cause the closure of the magnetically responsive contacts 62 and 52.

The 0.5 microfarad condenser 58 and the 200- ohm resistance 59, whichare connected to ground across the contacts til-52, serve to protectthese contacts during their operation from, current surges due toinductive discharge.

The period of closure of the contacts 62-452 is controlled by regulationof the flux through the electromagnet 10, which is continuouslyenergized from the 300-vo1t power supply 19 in series with the15,000-ohm resistance Bil. A current regulating circuit includes the2,000-ohm variable resistance Si in series with a 1,200-ohm resistance82, which acts as a variable shunt to ground across the circuit of theelectromagnet 10. The thermistor 65 in parallel with the resistance 64,is in series with the windings of the electromagnet l0, and functions tomaintain constant current with changes in temperature.

A separate control for adjusting the precise release position of thecontacts 62ii2 of the switch to is provided by the GOO-ohm variableresistance M, which is adapted to be switched in and out of thecurrent-controlling circuit for the energizing winding Hi, under controlof the relay 87', which is energized and deenergi'zed in synchronismwith the closure and release of contacts 60-62". The relay 81, which isenergized by means of the power source 88 connected to ground 92, isconnected to the Ellwood contact 62 through the junction J; When therelay 8'! is energized by closure of the contacts 52-452 connecting theground contact 86 to the circuit thereof, the number 1 armature engagesits 12 contact, thereby placing the resistance 9! in shunt to ground 99across the resistances 8| and 82. Operation of the relay Eli is notaffected by this reduction in voltage, since once the relay is in,operation, only a relatively small current is necessary to keep it so.

The magnetically responsive relay of the applicants invention may takeother forms than those of the embodiments shown and may be useful inother systems than the one herein described.

What is claimed is:

1. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of non-magnetic gaps therein, an electricalcontactor comprising a resilient contact-bearing magnetic member mountedin one of said gaps and adapted to be moved between contact closure andrelease under the influence of magnetic flux passed through said memberand said core, a control member of magnetic material, driving meansmechanical-1y coupled to said control memher for driving said controlmember in a repetitive cycle of movement into and out. of magneticbridging relation with another of said gaps whereby the closure andrelease of said magnetic member is dependent on the position of. saidcontrolmember, a magnetizing winding on said core,

means for supplying substantially constant current of a first value tosaid winding when said contactor is released, and means responsive toclosure of said contactor for changing said magnetizing current to asecond substantially constant value, whereby the time of closure of saidcontactor is repeatedly controlled by the current of said first value tocause closure of said member at a first position, the same in each cycleof movement of said moving member, and whereby the time of release ofsaid contactor is repeatedly controlled by the current of said secondvalue to cause release of said member at a second position, the same ineach cycle of movement of said moving member.

2. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of nonmagnetic gaps therein, an electricalcontactor comprising a resilient contact-bearing magnetic member mountedin one of said gaps and adapted to be moved between contact closure andrelease positions under the influence of magnetic flux passed throughsaid member and said core, a control member of magnetic material,driving means mechanically coupled to said control member for drivingsaid control member in a repetitive cycle of movement into and out ofmagnetic bridging relation with. another of said gaps whereby theclosure and release of said magnetic member is dependent on the positionof said control member, a magnetizing winding on said core, means forsupplying substantially constant current of a first value to saidwinding when said contactor is released, means responsive to closure ofsaid contactor for changing said magnetizing current to a sec: ondsubstantially constant value, and means in circuit relation with saidwinding for adjusting the value of one of said substantially constantcurrents with respect to the value of the other of said substantiallyconstant currents.

3. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of non-magnetic gaps therein, an electricalcontactor comprising a resilient contactbearing magnetic member mountedin one of said gaps and adapted to be moved between contact closure andrelease positions under the influence of magnetic flux passed throughsaid member and said core, a control. member of magnetic material,driving means mechanically coupled to said control member for drivingsaid control member in a repetitive cycle of movement into and out ofmagnetic bridging relation with another of said gaps whereby the closureand release of said magnetic member is dependent on the position of saidcontrol members, a magnetizing winding on said core, means for supplyingsubstantially constant current of a first value to said winding whensaid contactor is released, means responsive to closure of saidcontactor for changing said magnetizing current to a second'substantially constant value, and means in circuit relation with saidwinding for separately adjusting the value of each of said currents,thereby providing separate means for controlling the closure and releasetimes of said contactor.

4. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of non-magnetic gaps therein, an electricalcontactor comprising a resilient contactbearing magnetic member mountedin one of said gaps and adapted to be moved between contact closure andrelease under the influence of magnetic flux passed through said memberandsaid core,'a control member of magnetic material, driving meansmechanically coupled to said control member for driving said controlmember in a repetitive cycle of movement into and out of magneticbridging relation with another of said gaps, whereby the operation ofsaid magnetic member is dependent on the position of said controlmember, a magnetizing winding on said core, means for supplyingsubstantially constant current of a first value to said winding, meansresponsive to closure of said contactor for changing said magnetizingcurrent to a second substantially constant value, wherein said controlmember is magnetized, and wherein said current is poled to oppose themagnetization of said control member and of a strength insuflicient toprevent closure of said contact device by said control member.

5. A magnetic relay comprising a core of magnetic material having aplurality of non-magnetic gaps therein, an electrical contactorcomprising a resilient contact-bearing magnetic member mounted in one ofsaid gaps and adapted to be moved between contact closure and releasepositions under the influence of magnetic flux passed through saidmember and said core, and a control member of magnetic material, drivingmeans mechanically coupled to said control member for driving saidcontrol member in a repetitive cycle of movement into and out ofmagnetic bridging relation with another of said gaps whereby the closureand release of said magnetic member is dependent on the position of saidcontrol member, a magnetizing winding on said core, means for supplyingsubstantially constant current of a first value to said winding, andmeans responsive to closure of said contactor for changing saidmagnetizing current in said winding to a second substantially constantvalue, said control member comprising a permanent magnet whereby saidcontactor is closed and then released as said control member moves intoand then out of said bridging relation, said control member having adimension which is adjustable thereby to control the times of closureand release of said contactor.

6. A switch comprising in combination a substantially U-shaped core ofmagnetic material having a pair of legs, an energizing winding disposedon one of the legs of said core, means comprising a substantiallyconstant source for supplying current to said energizing winding, theother of said legs having a gap therein, an electrical contactor mountedin said gap, said contactor comprising a pair of resilient magneticstrips disposed in a direction parallel to at least a component of themagnetic flux produced in said gap by said energized winding acting onsaid core, said strips being mounted in overlapping spaced relation,whereby they are actuated to move into contacting position whenever themagnetic fiux in said gap assumes a predetermined strength, a shoe ofmagnetic material rotatably mounted for movement into and out ofmagnetic bridging relation with said legs at the open end of said core,whereby to vary the magnetic flux in said gap actuating said strips toclose and release contact under control of the movement of said shoe, acontrol circuit connected to said energizing winding, said controlcircuit including a pair of branches having separately adjustableattenuation, and means comprising an auxiliary relay having anenergizing circuit including said resilient strips, whereby closure orsaid resilient strips energizes said auxiliary relay, and contact meansunder control of said auxiliary relay and connected to one of saidbranches to change the attenuation of said control circuit bycontrolling the connection of said branch as part of said controlcircuit.

'7. In combination with a cyclically moving mechanical member and anauxiliary circuit to be operated in timed relation with the cyclicalmovement of said mechanical member, a control device, said controldevice comprising in combination a circuit-closing contactor comprisingmagnetic material, said contactor connected to said auxiliary circuit, amagnet having a plurality of gaps, said contactor positioned in one ofthe gaps of said magnet, an armature of magnetic material coupled tosaid mechanical member and moving synchronously therewith toperiodically change the reluctance through another of the gaps of saidmagnet by a sufiicient amount to cause a periodic closure of saidcontactor at the same time in each cycle of said mechanical mem ber, acontrol winding on said magnet, a substantially constant source of powerconnected to supply current to said winding, a pair of circuit brancheseach including an adjustable attenuator connected to said controlwinding, and means responsive to closure of said contactor forcontrolling the connection of at least one of said circuit branches withsaid control winding to change the current in said control winding fromone substantially constant value to another substantially constantvalue, whereby the instant and duration of closure of said contactor iscontrollable with respect to the cyclic position of said mechanicalmember.

8. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of non-magnetic gaps therein, a pair ofnormally separated resilient contactors of magnetic material interposedin one or" said gaps in a position to be moved magnetically from opencontact relation to closed contact relation under the infiuence ofmagnetic fiux passed through said contactors and said core, a controlmember of magnetic material mounted for a cycle of movement along afixed path into and out of magnetic bridging relation with another ofsaid gaps, a magnetizing winding on said core, means to supplymagnetizing current of a first value to said windin of such strength andconstancy as to cause said contactors to move into said closed contactrelation whenever a first predetermined point is reached in the cycle ofmovement of said control member into said bridging relation, and meanscontrolled by said contactor-s and operative for the duration of saidclosed contact relation for establishing the strength of saidmagnetizing current at a diiierent constant value such as to allow saidcontactors to resume said open contact relation whenever a secondpredetermined point is reached in the cycle of movement of said controlmember out of said bridging re lation.

9. A magnetic relay comprising in combination a core of magneticmaterial having a plurality of non-magnetic gaps therein, an armature ofmagnetic material interposed in one of said gaps and responsive underthe influence of magnetic flux passed through said armature and saidcore to move from a normal position to a second position, a pair ofelectric contacts, one of said contacts attached to said armature, saidcontacts positioned to make contact with each other in one only of saidarmature positions, a control member of magnetic material mounted for acycle of move- 9 ment along a fixed path into and out of magneticbridging relation with another of said gaps, a magnetizing winding onsaid core, means to supply a biasing current to said winding ofsuificient strength and constancy to force said armature 5 into saidsecond position whenever a first predetermined point is reached in thecycle of movement of said control member into said bridging relation,and circuit means controlled by said pair of contacts and operative onlyso long as said. armature is in said second position for establishingthe strength of said biasing current at a different constant value suchas to cause said armature to resume said normal position whenever asecond predetermined point is reached in lo the cycle of movement ofsaid control member out of said bridging relation.

10. A magnetic relay in accordance with claim 9 wherein a periodicallymoving member is coupled to said control member.

1.1. A magnetic relay in accordance with claim 9Wherein said controlmember ispermanently magnetized in a direction to alter the magneto- 10motive force in said core when in said bridging position.

ALFRED K. SCHENCK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED srri rns PATENTS Great Britain Mar. 21, 1941

